The present invention relates generally to vending machines, and more particularly to a mechanism for selectively locking and unlocking manually operated pull rods on vending machines.
Manually operated vending machines usually have some type of a locking device which prevents a consumer from manually operating the machine until a certain amount of money is inserted into the machine, at which time the locking mechanism is unlocked, thereby allowing the consumer to actuate the machine and receive the product desired. At least one such design of a locking mechanism includes a spring which holds a locking member in place. This spring must be overcome by the weight of the coins inserted therein. It has been determined that such a locking mechanism is not entirely reliable. The problem is that the coins themselves are not very heavy and therefore they do not produce enough energy to positively unlock the machine once the proper amount of money has been inserted therein. In certain of these devices there is also a high friction factor holding the interlocking members together, and it requires too much work to be done by a coin of small mass. Consequently, these prior art devices do not always unlock the vending machine and allow the consumer to receive the desired product as such machines were designed to do.
Consequently, there is a definite need for a locking and unlocking mechanism which does not rely on the weight of the coins for unlocking and furthermore for such a locking device which is reliable and not unduly complicated.
An object of the present invention is to provide an improved locking mechanism for a vending machine.
Another object of the invention is to provide a locking mechanism for a vending machine which is reliable and positive in its locking and unlocking functions.
Still another object of the present invention is to eliminate the need for the weight of coins to overcome springs in such a locking mechanism.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.